Greer said the U.S. will not tolerate retaliation from Canada but is hopeful Canadians may take a more conciliatory approach.

If the U.S. imposes 338 tariffs, Ottawa must weigh whether to retaliate, pursue slow legal action, or simply wait Trump out.

Greer said the U.S. will not tolerate retaliation from Canada but is hopeful Canadians may take a more conciliatory approach.